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5W40 vs. 0W40 — What's the Difference?

By Tayyaba Rehman — Published on January 27, 2024
Both 5W40 and 0W40 are multi-grade motor oils, but 5W40 has a slightly higher viscosity at lower temperatures compared to 0W40, making 0W40 better for colder climates.
5W40 vs. 0W40 — What's the Difference?

Difference Between 5W40 and 0W40


Key Differences

5W40 is a multi-grade oil where '5W' indicates the viscosity of the oil at low temperatures, and '40' signifies the viscosity at high temperatures. 0W40, with '0W', has a lower viscosity at cold temperatures, making it more fluid in colder environments.
The 'W' in both stands for 'winter', indicating their performance in cold weather. 5W40 provides good fluidity and protection in moderate to cold temperatures, while 0W40 is designed for optimal performance even in very cold conditions.
In terms of high-temperature performance, both 5W40 and 0W40 maintain a similar viscosity, providing stable lubrication in engines during hot operating conditions.
The choice between 5W40 and 0W40 often depends on the climate and the specific recommendations of the vehicle manufacturer. 0W40 is generally preferred in regions with extremely low temperatures.
Both oils provide good engine protection but 0W40 offers better cold start properties, which can be crucial for engine longevity in colder climates.

Comparison Chart

Low-Temperature Viscosity

Higher than 0W40
Lower, more fluid at cold temperatures

High-Temperature Viscosity

Similar to 0W40
Similar to 5W40

Cold Weather Performance

Good for moderate to cold climates
Better for very cold climates

Use Recommendation

Depending on climate and vehicle needs
Preferred in regions with low temperatures

Engine Protection

Effective overall protection
Enhanced cold start properties

Compare with Definitions


Has a higher viscosity at lower temperatures than 0W40.
My mechanic recommended 5W40 for better engine performance in autumn.


Maintains similar high-temperature viscosity as 5W40.
Despite the freezing winters, my 0W40 oil also performs well in summer.


Suitable for various vehicles according to manufacturer recommendations.
The manufacturer specified 5W40 oil for my diesel engine.


A multi-grade oil with lower viscosity at cold temperatures.
I use 0W40 oil for optimal engine performance in the harsh winter.


A multi-grade oil suitable for moderate to cold climates.
I use 5W40 oil for my car since it provides good protection in our region's climate.


Enhances engine longevity with better cold start properties.
Since switching to 0W40, my car's engine starts more easily on cold mornings.


Offers effective protection for engines in moderate climates.
Since moving to a milder climate, I switched to 5W40 oil for my car.


Recommended for regions with extremely low temperatures.
Living in a region with severe winters, 0W40 is my preferred engine oil.


Provides stable lubrication in a range of temperatures.
The 5W40 oil maintains its viscosity well during both summer and winter months.


Ideal for very cold climates, ensuring fluidity during cold starts.
My SUV runs smoothly in the snowy mountains thanks to the 0W40 oil.

Common Curiosities

What is the main difference between 5W40 and 0W40?

The main difference lies in their viscosity at low temperatures, with 0W40 being more fluid.

Is 5W40 oil good for high-mileage cars?

Yes, 5W40 can be suitable for high-mileage cars, depending on manufacturer recommendations.

Does 0W40 provide better engine protection in winter?

Yes, its lower viscosity at cold temperatures ensures better protection during cold starts.

Does 0W40 improve fuel efficiency?

It can improve fuel efficiency, particularly in cold conditions due to better fluidity.

Can I use 0W40 in a moderate climate?

Yes, while it's excellent for cold climates, it's also suitable for moderate climates.

Can I switch from 5W40 to 0W40?

Yes, if it aligns with your vehicle’s requirements and operating climate.

Can I use 0W40 in summer?

Yes, 0W40 maintains its high-temperature viscosity similar to 5W40, making it suitable for summer use.

Is 5W40 better for older engines?

It can be, especially if the engine requires slightly thicker oil for better lubrication.

How often should I change 0W40 oil in my car?

Follow your vehicle’s manufacturer guidelines, but typically it's similar to other oils.

Are 5W40 and 0W40 suitable for both diesel and gasoline engines?

It depends on the specific oil formulation and vehicle manufacturer's recommendations.

Can using the wrong type between 5W40 and 0W40 damage my engine?

Using the wrong viscosity can affect performance; always follow manufacturer recommendations to avoid potential damage.

Is 5W40 oil thicker than 0W40 at engine start-up?

Yes, 5W40 is slightly thicker at lower temperatures compared to 0W40.

Does weather affect choosing between 5W40 and 0W40?

Yes, 0W40 is preferable in colder climates, while 5W40 is versatile for various climates.

Are there any specific brands that are better for 5W40 or 0W40?

Quality can vary by brand; it’s best to choose a reputable brand that meets industry standards.

Do 5W40 and 0W40 have the same high-temperature performance?

Generally, yes, both have similar performance at high temperatures.

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Author Spotlight

Written by
Tayyaba Rehman
Tayyaba Rehman is a distinguished writer, currently serving as a primary contributor to As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.

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